Bottle closure



March 14, 1933.

A. H. wARTH v BOTTLE CLOSURE Filed April 4, 1930 mvl-:NToR

/J ATTORNEY,

Patented Mar. 14, 1933 UNITED STATES PATENT oEF'lcE ALBIN H..WARTH, 0F BALTIMORE, MARYLAND, AIKSSVGNOR TOgCROWN CORK & SEAL COMPANY, INC., or NEW YORK, N. Y., A coRronATToNoFNEw YORK BOTTLE cLosuRE Application Elea April 4, 1930. serialv Np. 441,461.`

My invention relates to bottle closures,A and more particularly to bottle closures of the type embodying therein a sealing disk carried by a skirted metallic shell. s

' Heretofore, it has been a common practice to produce bottle closures consisting of a metal shell having a fluted skirt, the inner face of the top of which shell had cemented thereto, a cushion disk which, in some in-A stances, was made of natural cork, and in other instances, of composition cork, formed of cork granules united by a suitable binder.

In orderto prevent oxidation of the exposed surface of the disk, discoloration thereof from the contents of a bottle or other container, disintegration of the material of the` disk when composition cork was used, and contamination of the contents of .a bottle or other container as a result of bacteriological action, it has long been the practiceto provide the exposed face of the cushion disk with a thin film of wax, or with what is known as a center spot -of specially treated paper, or of a metal foil. y

ile such caps have always given highly satisfactory results, the use of wax as a surfacing did not always meet the requirements of the bottler, particularly when the closures were used upon containers, the contents of which required sterilization, pasteurization or cooking after the closure had been applied thereto, since when subjected to high temperatures there was always the possibility that the Wax surface might be disturbed. Furthermore, there was also always the likelihood that tumbling the closures in the hopper of the bottle capping machine would disturb this coating. With some classes of beverages, including some spring waters, mineral waters whether natural or artificial, and foodstuffs having an acid content, the waxed cushions could not be used. To meet such conditions, center spot caps were produced, the material of the spot, however, varying for use with different liquids or substances.

In the production of center spot caps, there have always been manufacturing difficulties, due to the necessity of reasonable accuracy in the location of the centers, so as to expose a sufiicient surface ofthe material of the cushion about the center spot, to secure a proper sealing of the'container. This was due largely tothe tendency of the disk of the center spot moving in relation to the center of the cushion disk ywhen pressure was applied thereto in cementing` same in'position, re-

sulting from the viscosity of the cement used and the non-absorptive properties of the cushion disk.

I have -recently developed a center spot cap wherein the bonding agent between the center disk and the cushion disk consists'of gutta-percha tissue which has been found to adhere satisfactorily to an untreated surface of the cork, whether natural or composition, and to very materially reduce the wastage resulting from the center spot disks being offcenter in relation to the cushion disk.

It is desirable, even when center spots are used, that the exposed surface of the cushion disk shall be treated or receive a thin coating ofa material having the characteristics of the wax above referred to, but the presence of such wax precludes the use of the center spot caps in the bottling of beverages or' foodstuffs with which the ordinary waxed.

surfaced cushion disk caps could not be used. Furthermore, the wax coating upon disks was restricted to the exposed surface thereof, and whencenter spots were used, it was necessary to apply the Wax after the application of the disk.

The above condition was due to the fact that the cushion disk must be cemented to the shell to permit the handling of the caps in the capping machine, and the center spots must be cemented to the face of the disk so that the presence of wax throughout the areas where the use of cement was required prevented a proper bonding action. p

With the above conditions in mind, I have provided a bottle closure or other container cap employing a cushion disk of natural or composition cork, wherein the exposed surface of the cushion disk is provided with a thin, transparent coating of non-absorbent, acid resisting, linfusible and non-oxidizing material having sui'icient inherentije'siliency and elasticity to readily conform to'aiy ydistortion of the cushion disk during the application ofthe closure to a container. This coating will also serve, as did the wax coating, tovfill minute surface imperfections or voids in the cushion disk.

In addition to the characteristics above referred to, the surface coating may be applied throughout the-entire surfaceof the cushion disk and permit the more effective utilization of gutta-percha tissue as a binding material in aixing a centerv spot to the cushion disk,

since the rap-id coalescence of the fused guttapercha with this surface coating avoids that slippage which results in the accidental lo-y cating of such spots olf-center.

The invention consists primarily in a bottle closure embodying therein a metal shell, and a cushion disk formed of cork provided with a thin transparent coating of non-absorbent, acid resisting, infusible, non-oxidizing material having inherent resiliency and elasticity; and in such other novel characteristics as are hereinafter set forth and described, and more particularly pointed out in the claims hereto appended.

4lieferring to the drawing,

Fig. l is a bottom plan view of a center spft diskclosure embodying the invention; an

Fig. 2 is a cross section thereof..

Like letters refer to like parts in both of said views.

-In they accompanying drawing, I have shown the invention as applied to a bottle closure of the crown type, embodying therein a shell of the usual formation, the top 0f which is shown at a, and the fluted, outwardly ared skirt vof which is shown at b, the drawing being upon a muchv enlarged scale.

Within the metal shell is shown a cushion disk c which consists of composition cork. The metal shell is provided withthe usual inner coating of lacquer, and the cushion o is cemented thereto in' the usual manner. The entire surface of the cushion disk c is provided with a thin coating, a mere film, of

an unvulcanized rubber compound, having a low content of vulcanizing medium and a lWater soluble, accelerator, but no filler, so

that when subjected to a low temperature, or to Warm air,it will develop the properties of being non-absorbent', acid resisting, infusible and non-oxidizing While possessing suiicient.

inherent resiliency and elasticity tov readily conform to any distortion of the disk b when subjected to vpressure while being applied by a capping machine. Preferably, I use Water dispersed rubber in the compound, which is indicated at ai.

It is desirable to apply the coating d to only one surface of the disk c as by so doing manufacturing diiculties are reduced to a minition to any other portion of the cushion disk.

A closure having the exposed surface of the the cushion disk and the deleterious action of the contents of the bottle upon the disk, or ofthe disk upon the contents of the bottle, but ensures a more eifective sealing of a bottle as a result of the closure of minute openings in the surface of the cushion disk, and the conformation of the surface coating to the disk when distorted by the application of pressure when applying the closure toA 'a bottle or other container. This coating, how-7 ever, Will also greatly facilitate the application of 'a center spot, such as e, to the cushion disk, particularly when fusible adhesive, such as gutta-percha tissue indicated at f, is employed for binding such center spot disk to the cushion disk. rlhe gum ofthe surface coatingand the gum of the tissue,l upon the application of heat throughout the area of the disk e, will both become more or less tacky and thus not onlyl expedite the bindin action, as the material of the coating and t e tissue yset upon cooling, but avoid any material side slipping of the center spot disk because the coating is already bonded to the cork.

I have found, in actual practice, that it is desirable to produce the coated disks by applying a solution of Water dispersed rubber compound as described, to a sheet of 4cork or composition cork, and ycutting disks therefrom after the solution has become thoroughly dry. While,- during the cutting operation, the drag of the dies may remove small portions of the coating 'about the edge of the disks, this is immaterial so far as the eciency of a disk so coated is concerned. I consider this procedure preferable to attempting to coat previously formed disks by immersion, or other methods, although this procedure might be followed. A thinner and more uniform coating, however, can be secured in the manner I have above describede The center spot disk emay be formed of specially treated paper, tin foil, aluminum foil, or zinc foil, according to the character of the' beverage or foodstuff with which the closures are to be used.

For some uses, this center spot disk e may closure herein set forth, nor to the manufacturing methods described, .since it is obvious that such may be varied without departing from the spirit and scope of the invention.

I believe it to be broadly neW,-however, to provide a closure having a transparent coating of pure, semi-vulcanized rubber, or a material having similar properties, upon the surface thereof exposed Within a closure, and

)I intend ,to claim such broadly.,

Having described the invention, what I claim. as new and desire to have protected by Letters Patent, is

LA bottle closure embodying therein a metal shell, and a cushion disk formed of cork provided with 'a thin. transparent coating of non-absorbent, acid resisting, infusi-1 ble, non-oxidizing material having inherent resiliency and elasticity.

2. A bottle closure .embodying therein a metal shell, and a cushion disk formed ofl cork provided with a thin surface coating consisting of a film of semi-vulcanized rubber.

3. A bottle closure embodying therein a metal shell, and a cushion disk formed of cork provided with a thin coating of semivulcanized water dispersed rubber.

4. A bottle closure embodying therein a metal shell, and a cushion disk formed of cork provided upon the exposed surface thereof only with a thin surface coating con` sisting of a film of semi-vulcanized rubber.

5. A bottle closure embodying therein a metal shell, a cushion disk formed of cork provided with a thin transparent coating of non-absorbent, acid resisting, infusible, nonoxidizing material having inherent resiliency and elasticity, a center spot, and an adhesive having an aiiinity for .said coating material between said spot and the surface coating of the disk.

6. A bottle closure embodying therein a metal shell, a cushion disk formed of cork provided with a thin coating of semi-vul- 3'5 canized rubber, a center spot, and a stratum of guttwpercha between said spot and the rubber coating.

'e'. A bottle closure embodying therein a metal shell, a cushion disk formed of cork 40 provided with a thin coating of semi-vulcanized water dispersed rubber, a center spot,

and a stratum of gutta-percha between said spot and the rubber coating.

8. A bottle closure embodying therein a. metal shell, a cushion disk formed of cork provided upon `the exposed surface thereof enly with a thin coating of semi-vulcanized rubber, a. center spot, and a stratum of gutta- [w percha between said spot and the rubber coatin in witness whereof I have hereunto affixed my signature, this 31st day of March, 1930.

ALBINE H. WARTH. 

